India must prepare for changes in the great Himalayan water

News:  Environmental experts discuss how human actions are impacting Earth and India in Particular.

How is climate change reshaping dynamics which make our weather?

Greenhouse effect causes earth’s temperature to be well below the freezing point of water. The greenhouse effect is necessary for life on Earth.

However, increasing the amount of greenhouse gases increases the amount of energy going into the climate system and thereby affects weather.

Over the past 150 years, the amount of carbon dioxide, methane and other gases in the atmosphere have increased, largely due to the burning of fossil fuels.

How the climatic patterns are now changing in India and their implications?

Changes in distribution of precipitation that falls upon an area in a year: Many places now experience high intensity of rainfall in short span or the long periods of aridity. 

These weather changes influence two critical cycles. The first is the hydrological cycle, or the availability of water. The other is the cycle of the variations of temperature. These have direct impact on plant productivity, which forms the basis of all life.

Further, during the monsoon in India, precipitation has become more extreme with flooding.

Onset and duration of winter in areas which have a cold season: This appears to be ending faster. In much of northern India, if the cold season ends earlier and the hot season starts sooner, the entire pattern of sowing and harvesting crops will change

The rhythm of the seasons is central to agriculture which employs 45% of our population of 1.3 billion people.

Increasing Dry spells: Dry spells due to climate change will impact the dynamics of Earth’s third water tower, the Himalayas.

There are over 10,000 glaciers in the greater Himalayan Mountain chain. They are the source of the perennial rivers which flow across the northern part of South Asia.

If these glaciers are impacted by changes in temperature, their melt rate will change. That will affect people living even thousands of miles downstream.

A prolonged dry spell can impact both agricultural production and rural India’s consumption of goods and services.

Change in number of mild days: According to the research by Gabriel A. Vecchi, globally on average, the number of mild days, impacted by anthropogenic warming, will go down.

For India, the temperature of the warmest days will continue to increase. The temperature at night will also continue to increase.

The circulation of the winds in the tropics are slowing down: Alongside, the speed of certain extreme winds, particularly tropical cyclones, are seemingly increasing, in large part due to the warming ocean.

Other implications for India:

– Temperature variability affects economic growth: Research has shown that, warm countries, tend to grow slightly less in terms of per capita GDP in warmer years than cooler years. As a consequence, India’s per capita GDP is about 30% lower today than it would have been without global warming.

– Sea-level rise: oceans take up a lot of heat and consequently, they expand, leading to sea level rise. Further, ice on land also melts. That water, from ice caps, glaciers, etc., will run off into the oceans, causing further sea level rise.

What steps need to be taken?

Changes in pattern of land utilisation: In many sea-front cities low-lying areas have been subject to permanent structures. They restrict water flows and water percolation. Urban development must take this profound change into account.

Source: This post is based on the article “India must prepare for changes in the great Himalayan water” & “Humans have created an unknown climate —India’s per capita GDP is 30% lower due to this” & “Studying the weather is critical now — the tropics could have fewer mild days” published in TOI on 18^th Dec 2021.